Shock absorber



W. A. GEIGER SHOCK ABSORBER Nov. 20, 1945.

Filed Oct. 13, 1943 Zane/mr Wzllza' m'e'yer /W M l if Patented Nov. 20, 1945 UNITED STATES PATENTv OFFIC Application October 13, 1943, Serial N0. 506,083

3 Claims.

This invention relates to an improved shock absorbing device which is especially adapted for snubbing action of the truck springs of railway cars. i

One of the objects of the invention is the provision of a shock absorber functioning as a snubbing device for the truck springs of railway cars, which shall have substantially uniform resistance to the relative movement of the truck parts.

A further object of the invention is to provide a shock absorberwhich shall serve in lieu of at least one of the coil springs of the usual set of springs employed in each cluster of truck springs and in which the snubbing action is obtained by two tubular members, one of which is urged into frictional engagement with the other by its own resiliency.

These and other objects of the invention, which will more clearly appear from the description and appended claims, are accomplished by a friction shock absorber structure in which the movement of a plunger within a cylindrical casing is frictionally resisted by a tubular frictional element positioned between the casing and the plunger,

and forced into frictional engagement with the.;

surfaces by virtue of its own inherent resiliency. Referring now to the drawing which forms a -part of this specification,

Fig. -1 is a vertical sectional view of a shock absorber embodying the invention;

Fig. 2 is a transverse section on the line 2-2`:

projection of the bottom spring follower for the l truck springs. The annular side wall of the shell at its upper end portion 3 is made thicker to provide an interior annular friction surface 4, the diameter of which is smaller than the interior of the shell proper.

The follower or plunger member B extends within the open upper end of the casing in telescoping relation thereto sol as to have movement lengthwise thereof. This plunger is in the form of a hollow, cylindrical, tubular member 5, open Athan the annular friction surface 4 of the casing,

so that the plunger can be telescoped within the casing in assembling the structure. The plunger extends beyond the upper end of the casing su'- ciently to kallow for relative movement of the members, and its upper end is closed by the top wall 'l which is extended laterally to form an annular flange 8 of substantially exterior diameter of the casing. Its upper wall has a central depression or recess 9 which forms a seat for the usual centering projection of the top spring follower `platefor the truck springs. The cylindric-al portion 5 of the plungerk is sufficiently less .in diameter than the diameter 0f the friction surface 4 of the casing, to provide an annular space I0 for the reception of the friction element D,

The friction element D is in the form of a split tubular or cylindrical member of sufficient length to fit between the flanges 6 and 8 of the plunger. It is made of spring steel and its exterior surface Il has frictional engagement with the annular lfriction surface 4 of the casing continuously throughout its circumference. The proper degree of frictional engagement of this element is obtained by making the element normally of larger exterior diameter than the diameterofthe .friction surface 4 and then contractingit against its own spring resistance in assembling it in the casing Thus, in assembled relation, 'the expanuniform diameters of the friction element D and.

the friction surface 4 throughout their length.

The spring resistance C to the 'telescoping movement of the plunger in the casing is provided by the concentrically disposed inner and outer coil springs l2 and I3, respectively. The inner spring extends from the bottom of the casing upwardly into-the hollow plunger to the upper wall 1 thereof, against which the upper endof the spring is seated. The lower end of the spring is seated upon the boss 2 of the casing. The outer coil spring I3 has its lower end seated on the bottom wall cf the casing at its upper end bearing against the flange 6 of the plunger.

In the modified form of Fig. 3, the structure is identical with that just described and shown in Figs. 1 and 2, with the exception that the wall of the friction element D is formed in waves or corrugations which extend lengthwise of the member so that the entire area of its `exterior surface is not: in. engagement. with the friction surface 4f ot the casing.. Instead, the-*outer apices I4 of the corrugations bear against the friction surface 4 at circumferentially spaced intervalsg,

. tl'ie. corru'galtibnsi will expand against; the' friction Surface .4 of --tlie ca sirig` to'. provide the desired f-ictionall resistance to the movement of the plunger;

'Ine' operation ofl my improved shock4 absorber snubbe'r is'asj foll'owsi". Assume' that. the parts are the position shown in the drawing and that tlie. devi'cley is mounted' in the car truck between the? bottom and't'QpV spring; follower' plates of the .-s'pring' cluster... Upon con'lpressionof the' spring cluster of Vtliei truok'tlie casinggA and plunger B willbe fcrcedtowardeacn other,Y thev plunger being forced' into the. casing aga-inst the' opposition of'. tbesprings t? and f3. since the friction elements. D move. with the plunger, it is in sliding engagement. Wtli the ctlon' `surface 4` of the casing arid; provides` the necessary frictonal' resistance to; snub the actionA of" the truck springs and, reduce the. oscillations of; said' springs to a desired minimum.` Upon the reverse; action of the truck: springs',t that; is. upon the. expansion thereof', .the plunger Bf and. casing A move relatively apart undef the expansive action of the springs; IZ and I3, whereupon the frictional engagement ofthe element. Dwith the casing again *.snubs, the. action of. the truck'. springs.

lclam; L. The combination ofi a friction casing open at', one, endl and having an interior, longitudinally extending, annular friction surface at said open end, a plunger movable lengthwise within the casing in concentric relation thereto, said plunger having laterally projecting anges at Ithe inner and outer ends thereof, a. longitudinally disposed metal tubular spring member split lengthwise and expanded byl itsk own resiliency against the annular' friction surface ofithe casing,r said member being embraced between said anges of the plunger so as to be moved in unison with the plunger and having direct frictional engagement with the annular friction surface of the casing, and springs within` the casing opposing inward movement of theplunger.

2t Ina shock absorber, the combination of a frictioncasing having an interior, longitudinally extending; annular friction surface, a plunger telescoped Within the casing in concentric relat'i'on to said' annular friction surface, said plunger casing being relatively movable in lengthwise direction and said plunger being spaced from said frictionY surface, atubular spring friction member 'disposed' concentri'cally of said friction surface in the space between saidv plunger and said friction surface and being under compression betwee'n'safid frictionfsurace and saidv plunger, the

'wall' ofY said: friction member being corrugated lengthwise to provide a plurali-ty of spaced riblike portions in frictional contact with said friction surface, and means within the casing yieldingl-'y opposing inward movement of the plunger. 2l. In a shock absorber, the combination ofV a friction casing7 open at one endE and having an annular interior, longitudinally extending, frictionsurface` at' itsk open' end, a. cylindrical tubular plunger movable'- lengthwise within the casing and concentrically spacedv therefrom toY provide an annular space between itself and the friction surface, said plunger havingy laterallyproj'ecting flanges a-t' itsE inner and outer ends, a tubular, longitudinally disposed, spring friction member embraced between saidanges to be moved in unison with the plunger, said friction member being; iiuted-v lengthwise to provide a plurality of longitudinal ribs onits interior and exterior surfaces aand being' under compression between the fric-tion surface ofthe casing and the exterior wall of theplun'ger, and springs, within the casing opposing the inward movement ofthe plunger.

WILLIAM A. GEIGER. 

